Field of Invention
The present invention relates to a valve, and more particularly to a valve which has at least three openings.
Description of Related Arts
Valves are widely applied in a wide variety of professions. A valve having three or more channels is very useful. For example, two valves according to the prior art are applied to a water heater, as shown in FIG. 1 of the drawings. An inlet valve 1, one of the two valves, is connected to an inlet of the water heater, so as to control the inflowing of cold water. An outlet valve 2, the other one of the two valves, is connected to an outlet of the water heater, so as to control the outputting of hot water in the water heater.
The water heater may remain some dirt in after being used for some days, so either the inlet valve 1 or the outlet valve 2 is provided with a drain opening being used to drain the dirt in the water heater.
As shown in FIG. 1 to FIG. 2C of the drawings, the inlet valve 1 provides three channels 1a, 1b and 1c. The channel 1a is communicated to the inlet of the water heater. The channel 1b is communicated to a water supply pipe. The channel 1c is provided to drain. The valve 1 has a first ball 1d and a second ball 1e. The first ball 1d has a cavity 1f having three openings 1g, 1h and 1i. The inlet valve 1 has an inflow communication state and a drain communication state.
At the inflow communication state of the inlet valve 1, the opening 1g communicates the cavity 1f to the channel 1a, and the opening 1h communicates the cavity 1f to the channel 1b, so that the water from the water supply pipe can inflow into the water heater through the channel 1b, the cavity 1f and the channel 1a. At the inflow communication state of the inlet valve, the opening 1i faces to the channel 1c, but the water in the channel 1a and 1b will not outflow from the channel 1c due to the blocking of the second ball 1e, as shown in FIG. 2A.
The inlet valve 1 further comprises two valve handles 1j and 1k respectively controlling the direction of the two balls 1d and 1e. The ball 1e provides a through-hole 1l. When there are some dirt in the water heater needs to be cleaned, one must operate the handle 1j first to rotate the ball 1d, so that the ball 1d blocks the communication between the cavity 1f and the channel 1b, so as to ensure the water in the channel 1b will not enter into the cavity 1f, and ensure the water in the cavity if will not enter into the channel 1b. Then the handle 1k should be operated to drive the ball 1e to rotate, so that the through-hole 1l communicates with both the cavity if and the channel 1c, so that the water with dirt in the water heater can be drained through the cavity 1f, the through-hole 1l and the channel 1c. The operating is complex and strict. One must apply two operating steps. And the order of the two operating steps should not be reversed. If the operating order of the two valves 1k and 1j is reversed, dirt in the water heater may enter into the channel 1b, and the water in the water supply pipe communicating with the channel 1b may be polluted by the dirt.
As shown in FIGS. 1, 3A, 3B, 3C and 3D of the drawings, the outlet valve 2 has a structure similar with the inlet valve 1. What is different from the valve 1, the valve provides four channels. A ball 2d provides four openings. A fourth opening 2m of the ball 2d communicates a cavity 2f of the ball 2d to a fourth channel 2m, and further to a relief valve 3. Similarly, if there is some dirt in the water heater needs to be drained via the valve 2, one must operate both a handle 2j and a handle 2k. 
Whether the valve 1 or the valve 2, the structure is complex, and has so many components. For example, at least two balls and at least two handles are provided. The more components result in that the valves occupy much more space. The maintaining of the valves becomes a harder work. The complex structure also gives each valve a complex appearance, that makes the surrounding of the water heater messier, that will bring much discomfort feeling to consumers.
FIG. 4 illustrates a valve 4 according to the prior art. The valve 4 provides three channels 4a, 4b and 4c. The channel 4a is provided to communicate with a device requiring water. The channel 4b is provided to communicate with a water supply device. The channel 4c is provided to drain. Comparing with the valves 1 and 2, the valve 4 has only one ball 4d and only one handle. The ball 4d has a cavity 4f having three openings 4g, 4h and 4i. At an inflow communication state of the valve 4, the opening 4g communicates the cavity 4f to the channel 4a, and the opening 4h communicates the cavity 4f to the channel 4b, so that the water from the water supply device can flow into the device requiring water through the cavity 4f At the inflow communication state of the valve 4, the opening 4i faces to the channel 4c, but the water in the channels 4a and 4b will not outflow from the channel 4c due to a sealing member 4j and a cover 4k are provided. The sealing member 4j is provided to prevent the water in the cavity 4f from being leaked to the surface of the ball 4d through the opening 4i. The cover 4k is provided to prevent the water in the cavity 4f from outflowing through the channel 4c. At a drain communication state of the valve 4, the ball 4d is driven to rotate, so as to block the communication between the cavity 4f and the channel 4b, and the channel 4a and the channel 4c communicate with each other through the opening 4i, the cavity 4f and the opening 4h, so that the water from the channel 4a can be drained. As mentioned above, at the inflow communication state, the cover 4k plays an important role of blocking, wherein the cover 4k may bear great pressure from the water in the channel 4c. The pressure from the water in the channel 4c may bring a risk of damaging the cover 4k. If the cover 4k is damaged, the water from both the channel 4a and the channel 4b may be leaked out, that may damage the environment of a house. Even if the consumer has found the damaging of the cover 4k timely, and the leaking is avoided, the damaging of the cover 4k makes the valve 4 cannot be used any more before the cover 4k is repaired or replaced.
It is worth to be mentioned that, at the inflow communication state, the passage of inflowing of the valve 4 is not so straight due to the water from the channel 4b to the channel 4a may pass through part of the channel 4c, so the water from the channel 4b to the channel 4a may pass through many corners which may store dirt easily. The dirt stored in the corners may enter into the device requiring water together with water from the channel 4b. Then the device requiring water will be polluted. The valves 1 and 2 also have this kind of hidden trouble.